hmmm not sure the exact temperature/degree but I know that hot tubs, jacuzzis, and saunas should be avoided. As for hot bath tub, some say it's not good, some say it's okay I think it just all depends on how much you can take, your body will let you know when to get out. I love taking baths, and somtimes I can't lie in there as long as I want because I can feel my body temp just rising and rising and I just cant take it...but I stay in for about 15 minutes.